This invention relates to polyaryl ether, high temperature lubricants which contain antioxidants.
There are only a few classes of compounds that qualify as high temperature fluids, that is, fluids used at temperatures above 300.degree. C. A well known class of such fluids are the polyaryl ethers. While generally stable, these lubricants can undergo oxidation at very high temperatures which leads to increased viscosity and shortened useful working life of the fluid. Therefore, it is desirable to find new and effective additives that serve as antioxidants for high temperature lubricants. Ravner et al. have reported the addition of various inorganic salts in polyphenyl ethers as antioxidants in ASLE Transactions, volume 15, pages 45-53 (1972) and in ASLE Transactions, volume 18, pages 1-4 (1975). However, the inorganic salts disclosed therein do not perform as well as is desirable.